Services

Services are an abstraction of ports and are the commonly used way of inter-process communication outside of the kernel. While handles of regular ports are retrieved from svcConnectToPort, service handles are retrieved through the port srv: ("service manager").

When a service is registered, svcCreatePort is used without a port-name. This means that the port is inaccessible via the port SVCs outside of sm-module. See below for getting a session handle for sending commands to services.

Processes with PID less than or equal to the number of NATIVE_FIRM built-in modules (fs, sm, pm, pxi, ldr) have access to all services. This value is obtained from svcGetSystemInfo. Other processes are limited to access services listed in their service access control list, as passed to SRVPM:RegisterProcess.

Attempting to use GetServiceHandle with a service that the process has access to when that service isn't registered will block until it is registered.

Service Manager Port "srv:"

Command Header	Description
0x00010002	RegisterClient
0x00020000	EnableNotification
0x00030100	RegisterService
0x000400C0	UnregisterService
0x00050100	GetServiceHandle
0x000600C2	RegisterPort
0x000700C0	UnregisterPort
0x00080100	GetPort
0x00090040	Subscribe
0x000A0040	Unsubscribe
0x000B0000	ReceiveNotification
0x000C0080	PublishToSubscriber
0x000D0040	PublishAndGetSubscriber
0x000E00C0	IsServiceRegistered

It appears these "port" commands can be used for transferring arbitrary handles, however GetPort still uses the same service-access-control validation as GetServiceHandle. Despite this fact, it appears that a "port" and a service with the same name can coexist independently.

Service Manager Process-Manager Port/Service "srv:pm"

Command Header (port), prior to 7.0.0-13	Command Header (service), post 7.0.0-13	Description
0x04010042	0x00010042	PublishToProcess
0x04020040	0x00020040	PublishToAll
0x04030082	0x00030082	RegisterProcess
0x04040040	0x00040040	UnregisterProcess

Prior to to 7.0.0-13, the commands listed for "srv:" were also accessible under this port with the same command-headers. Starting with 7.0.0-13, the "srv:pm" port was changed to a service. With this change, commandIDs for these commands were changed. "srv:pm" was originally vulnerable, this was fixed with 7.0.0-13, see here. Originally any process could use "srv:pm", however starting with 7.0.0-13 only the built-in NATIVE_FIRM sysmodules have access to it. The only system title which uses "srv:pm" is the Process Manager.

Notifications

ID	Published by	Subscribed by	Description
0x100		Not Needed	This indicates that the recipient must terminate.
0x101	PTM	NS	Signaled on sleep mode entry.
0x102	PTM	NS	Sleep Mode related?
0x103	PTM	NS, CSND, NWM, AC, NIM	Fired on sleep mode entry (Kernel state is modified by PTM after publishing this)
0x104	PTM	HID	This indicates that the system is entering sleep mode. (Kernel state is modified by PTM before publishing this)
0x105	PTM	NS, DSP, CSND, GSP, CODEC, CAMERA, HID, QTM, MIC, IR, NWM, FRIENDS, AC, CECD, ACT, NDM, NIM	This indicates that the system has exited sleep mode.
0x106	PTM	NS, MIC, AC, NEWS, CECD, BOSS	Fired after sleep mode exit.
0x107	PTM	NWM, CECD, BOSS, NDM, NIM, NEWS	Unknown.
0x108	PTM	GSP, QTM	System is going to Power Down.
0x109	CFG	GSP	CFG block 0x00050001 has been modified, change LCD brightness/PWM settings
0x10B	CFG	CAMERA	?
0x10C	PM		A Regular application has started.
0x110-0x11F	PM	NS	Sent on application exit. See PM launch flags.
0x179	PM	PTM, NS	All processes other than PTM and NS have terminated.
0x200		NS	Signaled just before sleep mode is exited from.
0x202	MCU	NS	POWER button pressed
0x203	MCU	NS	POWER button held long
0x204	MCU	NS	HOME button pressed
0x205	MCU	NS	HOME button released
0x206	MCU / NWM	NWM	The physical Wi-Fi slider state changed
0x207		MENU	SD card inserted
0x208		MENU	Game cartridge inserted
0x209		NS, MENU	SD card removed
0x20A		NS, MENU	Game cartridge removed
0x20B		NS, MENU	Game cartridge inserted or removed
0x20C	MCU	PTM	Published on a fatal hardware condition, when the MCU WDT triggers, ptm throws fatal error F960D407 in receipt of this
0x20D	MCU	GSP	Charger plugged out.
0x20E	MCU	GSP	Charger plugged in.
0x20F	MCU		Published by the mcu module when (bitmask & 0x8000) is true (started charging). This bitmask is obtained by reading i2c register 0x10.
0x210	MCU		Published by the mcu module when (bitmask & 0x4000) is true (stopped charging). This bitmask is obtained by reading i2c register 0x10.
0x211	PTM		Battery very low (5%)
0x212	PTM		Battery low (10%)
0x213	NS	CODEC, HID, GSP, CAMERA, MIC, NDM, QTM, PTM	Shell opened.
0x214	NS	CODEC, HID, GSP, CAMERA, MIC, NDM, QTM, PTM.	Shell closed.
0x300	AC	NDM, MENU	Signaled after sleep mode exit and during system boot.
0x301	AC	FRIENDS, NDM	Signaled just before sleep mode is exited from.
0x302	NWM	NDM, SOCKET, FRIENDS, AC	WiFi is turning off, triggered by using the WiFi switch on O3DS models and the toggle in the N3DS HOME menu (maybe disconnecting from any connected networks?)
0x303	NWM	CECD, NDM	WiFi has turned off. (fires shortly after 0x302)
0x304	NWM	CECD, NDM, SOCKET	WiFi was turned on.